1. Field of the Invention
The present invention generally relates to pumping apparatus and, more particularly, is concerned with an apparatus for pumping water from rise and fall motion of waves.
2. Description of the Prior Art
One of the more promising renewable sources of energy is ocean waves. Many devices have been proposed in prior art patents and literature for converting the energy of waves into a mechanical motion for performing work, such as generating electricity. In an article appearing in the September 1979 issue of IEEE Spectrum magazine entitled "Exploiting Wave Power", B. M. Count states that the first recorded patent was granted in 1799 to a Frenchman, M. Girard. Count goes on to state that all wave-power inventions to date have been conceptually simple, utilizing floats, flaps, sloping ramps or other "wave traps," or stationary air-pressure chambers and similar devices. He cites the emergence of two major categories of devices: dynamically active devices and passive devices. In the active device, the structural elements move in response to the wave, with power being extracted through the relative motion of the elements. A passive arrangement captures the wave energy with a relatively large, immovable structure. Being both bulky and relatively inefficient, passive devices are the least promising among suggested wave-power conversion schemes.
In a paper given in 1988 in Honolulu, Hi., entitled "Wave Energy: A Survey of Twelve Near-Term Technologies", investigators George Hagerman and Ted Heller grouped the major technologies for wave power conversion into five categories: heaving devices, heaving and pitching devices, pitching devices, oscillating water columns, and surge devices. Heaving devices use only the vertical motion of floats on waves to stroke various types of pumps. Combined heaving and pitching devices absorb energy from two or more motions of the waves, such as heave, pitch and roll. An oscillating water column device employs wave-induced motion of an entrained column of seawater as the driving force. Surge devices make use of a wave's forward horizontal force.
U.S. Pat. No. 4,996,840 which issued on Mar. 5, 1991 to the Robert P. Marx, the inventor of the present invention, and which thus does not constitute prior art to the subject invention, discloses an apparatus for generating rotary motion from rise and fall motion of waves. In its basic components, the rotary motion generating apparatus includes (a) an outer hollow sleeve, (b) a float sealably attached across the upper end of the outer sleeve to define an interior cavity, prevent entry of water into the cavity and provide the outer sleeve with sufficient buoyancy to floatably follow up and down motion of waves, (c) an inner hollow sleeve fitted telescopically within the outer sleeve, and (d) an anchoring arrangement attached to the inner sleeve for restraining it from following up and down motion of waves with the outer sleeve and float. The outer sleeve will slidably reciprocate, or move up and down, relative to the inner sleeve as the outer sleeve and float floatably follow up and down motion of waves and correspondingly will draw a flow of water upwardly and force a flow of water downwardly through the inner sleeve. The rotary motion generating apparatus also includes a rotary motion producing mechanism mounted within the inner sleeve intersecting and engaging the flow of water through the inner sleeve. In response to flow of water in either direction, upwardly or downwardly, through the inner sleeve, the rotary motion-producing mechanism continuously produces rotary motion in a single direction.
It has been perceived by the inventor herein that the basic components of the above-described apparatus producing reciprocal upward and downward movement of the outer sleeve relative to the inner sleeve can be employed to produce additional useful work, other than just that of rotary motion.